The invention relates to a tire of a vehicle, in particular a motor vehicle, with a tread for rolling on a driving surface and with a plate-shaped sensor element, which is mounted on the tread. Furthermore, the invention relates to a tire sensor element for mounting on a tread of a tire of a vehicle.
At the present time, a broad spectrum of tire and electronics manufacturers are developing tires with sensor elements. The sensor elements are used predominantly for monitoring the tire pressure of the respective tire and, in particular, for detecting a sudden pressure loss in the tire. In such a case, the pressure loss in the tire that is caused by the puncture of the tire carcass has to be indicated forthwith to the driver, so that the driver can react accordingly and, for example, decelerate the vehicle to a lower speed.
However, when the tire carcass is punctured, there is at the same time the highly relevant probability that the sensor element, located in the tire carcass, will be damaged by the object that caused the puncture.
There is therefore needed a tire with a sensor element such that a significantly higher reliability in terms of detecting a pressure loss due to a puncture in the tire carcass can be guaranteed.
This and other needs are met according to the invention, which provides a tire of a vehicle, in particular a motor vehicle, with a tread for rolling on a driving surface and with a plate-shaped sensor element, which is mounted on the tread. In this case, the sensor element is mounted so as to be oriented essentially perpendicular to the adjacent tread area. The perpendicular arrangement results in a significantly smaller area of the sensor element being exposed, when viewed from the direction of the tread, to any potential external influence due to a puncture.
In a first advantageous further development of this solution according to the invention, the sensor element is mounted in a resiliently swivellable manner on the tread. The resilient swivelling enables an intentional deflection on the part of the sensor element in the case of an external influence due to an object penetrating the tire.
In a second solution according to the invention and simultaneously advantageous further development, the side of the sensor element that faces the adjacent tread area is designed with a puncture-inhibiting protective layer. The protective layer, in particular in the form of a metal plate, protects the sensor element and deflects any object that may penetrate there such that the object cannot damage the sensor element.
In a third solution according to the invention and simultaneously advantageous further development, the sensor element is mounted on the adjacent tread area so as to be foldable due to an external influence. The foldably mounted sensor element can dodge the influence of an external body by way of a suitable folding movement.
In a fourth advantageous further development, the side of the sensor element that faces the adjacent tread area is designed with an outer face, which slopes in the direction of this tread area. The sloping outer face leads to a sliding off of any external body that may have penetrated there.
Furthermore, the invention provides a tire sensor element that is intended to be mounted on a tread of a tire of a vehicle, is configured in the shape of a plate, and has a puncture-inhibiting protective layer on one of its side faces.
In a first alternative and simultaneously advantageous further development of this solution according to the invention, the side of the tire sensor element that faces the adjacent tread area is designed with an outer face, which slopes in the direction of this tread area.
The invention is based on the recognition that in the case of a plate-shaped or a flat sensor element that is oriented parallel to the adjacent tread there is a relatively high probability that the sensor element will be damaged by a tread-puncturing object exactly at the instant that a dangerous pressure loss is supposed to be indicated. Although a defective tire sensor element can be detected by the respective control unit after some time, it is not clear even then whether only the sensor element has failed or whether at the same time, there was a loss in pressure. However, it is often the case that a sudden loss in pressure will result in a sudden deflation of the tire (particularly at high driving speeds) with an extremely disadvantageous dynamic behavior of the vehicle and potentially fatal consequences.
Such an event is especially hazardous if the external body that has punctured the tire has destroyed the tire sensor element, but the tire does not show any notable loss in pressure at that time. If the driver were to check the tire pressure upon an inactive notification message of the sensor element, the driver would find almost no loss in pressure. The external body would then become loose and fall out when the driver resumed driving.
Not until then would there be a sudden pressure loss that the driver would not notice without an additional indication in the display.
To date it has been assumed that a puncture-induced pressure loss and the failure of the respective system monitoring the tire pressure are two separate independent events, the simultaneous occurrence of which is highly improbable. However, at variance with this assumption is the fact that the probability of a simultaneous occurrence can be calculated and is not at all insignificant. If one assumes that the plate-shaped sensor element has an area of 3 cm2 and that the tread has, for example, an area of 2,298 cm2, then the probability of the two aforesaid events occurring at the same time is 1:766. This probability can be halved to 1:1,532, if one assumes that only half of the penetrating objects are so long that they will “fatally” hit the sensor element. Given a million vehicles, an average kilometrage of 15,000 km and a flat tire probability of once every 100,000 km, the result is 150,000 flat tires per year. Of these 150,000 flat tires, divided by 1,532, equals 98 such flat tires, where a puncture and a “sensor death” will likely occur at the same time.
The proposed solutions according to the invention largely reduce these problems in a simple and simultaneously cost effective way. Hence, in the event of tire defects in vehicles equipped with a tire pressure monitoring system, a significant improvement in the driving safety would be achieved in a simple way by means of the invention.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.